Reduction of copper oxide with nickel

ABSTRACT

A METHOD OF REDUCING AN AQUEOUS SLURRY COMPRISING CUPRIC OXIDE AND CUPRIC HYDROXIDE AND MIXTURES THEREOF WHICH COMPRISES REACTING SAID SLURRY IN THE PRESENCE OF HYDROGEN AND A SUPPORTED NICKEL CATALYST FOR A PERIOD OF ABOUT 1-6 HOURS AT 80-150*C., AND MODERATE SUPERATMOSPHERIC PRESSURE (5-10 ATMOSPHERES). THIS METHOD PRODUCED A CONVENIENT PRODUCT OF REDUCED COPPER OXIDE FOR INPUT TO A COMMERCIAL HYDROLYSIS OF NITRILES (SUCH AS ACRYLONITRILE) TO AMIDES.

ni ed O ABSTRACT 01 THE DISCLOSURE A method of reducing an aqueous'slurryfcomprising cupric oxide and cupric hydroxide and mix res thereofi which comprises reacting said slurry in the presenceof hydrogen and a supported nickel catalyst for a period' 'of about 1-6 hours at 80-150? CL, and moderatesup'eratnijospheric pressure ('5-10 'atmosphe s). i This method produced a conveni productfof reduced, copper oxide for inputto er'coliun 'al'hy'drolysis ,of nitriles (such asacrylonitrilp' i Q.

INTRODUCTIGJN- The present invention relateslt'o a duction of a reduced copper oxide mediatelyfor utilization asin hydrolysis of nitriles such a as a'crylamide. The pre'senti cupric oxide, cupric hydrojide, W the form of'an aqueoussliirryb ea the presence of hydrogen wither of a hydroxide and asuppdrted fiickel catal of about 1 6 hours at froni'80';l50' C. a superatmospheric pressures (5 10 atn'n'rsph'eres)w This same slurry'conta ining reduced'copper oxide cata lyst may then be used i'na continuous proeessrortfie hy drolysis of nitrile to amide as by the addition of acrylonitrile and formation of acrylamide proceeding according to 3,597,481 Tefertiller et a1. and 3,631,104 Habermannet al., both to Dow Chemical Company, which are"'ncorporated by reference.

Production of acrylamide by catalytic hydrolysis has; received significant patent attention in the currentiar For example, 3,631,104 Habermann et at. (Dow) redites the production of reduced copper oxide catalyst ate-column 3, specially setting out hydrogen reduction. Also" of in-.fterest is the following literature citation: C. Paal, Berichte, 47, 2202-2209 (1914), which discloses the usef-f-bf pal-j. ladium to reduce copper hydroxide and copper oxi taining the sodium salt of protalbinacid. The present inyention designed as an im rove ent. overthe known'art in-Ithat'tlie d oxides'farid hydroxides may; he catalyst and, furthermorer, t A oxides or higher valences 'o c ppe aqueous slurry so -.that,commerc: ly the, be utilized asinprit for .co "er all; nitrile. .v The term reduced cop e at column3 oflthe I -Ia berma t. indicates a catalyst where'n at least v per content has been reduced to cuprous oxide ltisfurther notedthatthe cuprous oxide pro 1 may contain'a minor amo 1 low) cuprous. hydroxidot, A d 1 I present invention are the black cupric oxide, blue copper hydroxide, and mixtures of the same. Such unreduced cop am monium 3,795,629 Patented Mar. 5, 1974 'per compog nds-maybe admixed in the natural state with reduced copperoxides in a minor amount and in such case the thrust of the invention is to increase the percentage of reduced copper oxide. The success or efiicacy of the process will be evidenced by optical or visual signals such as by the characteristic red color of the cuprous oxide product.

. Y THE SLURRY 'Asa pre-reactant, a source of cupric ion may be utilized --'selected 'from such copper salts as CuCO C11(NO3 2 31 120, 51 120, etc.',- as well as utilizing cupric hydroxide. By well-known techniques as, forexample, set out in 2,474,497 Rowe (Lake Chemical Company), the cupric hydroxide is formed by addition of alkali metal hydroxide and the complex by the addition of ammonium hydroxide.

A- t'yp'icalprocedure for the production of the oxides and hydroxides from'the saltsis heating the ammonia I, treated salts in alkali metal hydroxide solution at about F., followed by oven drying of the precipitate at from 70 1'10 C. for at least one hour to remove the fugitive or volatile anions.

- The" aqueous slurry is prepared by adjusting the water content'of'the unreduced cupric oxide/hydroxide mix to wherej'the ratio of cupric to water or aqueous in the slurry isin' the ratio from about 1:10 to 1:20.

Furthermore, in the formation of the slurry, it has sbmetimes been found advantageous to add a small amount 1 2'%by weight) of modifying heavy metal salts selected from' Zn or Fe.

I FORMATION OF THE CATALYST Thecatalyst of choice in the present invention is a supported nickel catalyst wherein 570% by weight of nickel=is .coated on a carrier. The carriers used in this thereof,It has been found that comparatively the nickel in this form shows yield advantage in nitrile conversion to amide over similar platinum-type catalysts.

Such nickel catalysts are known and commercially available. A typical catalyst is Girdler Corporations G49A or 6493 which are 65% and 50% nickel on kieselguhr clay respectively. The nickel is utilized in catalytiequa'ntities and together with the sodium hydroxide,

which may be added to the slurry, is present in about Q.05 0.5% by weight of the slurry containing the reactant unreduced cupric oxide.

I'II IfthG reduction of the cupric oxide to the active cuprous state, in addition to the presence of the nickel,

. arolofs edjk'ettle hydrogen atmosphere is necessary in the processfThe reaction advantageously may be carried out at from" 150 C. and conveniently at a moderately s'uperatnrospheric pressure of 5-10 atmospheres or optimally under pressure of 200-240 psi The preferred temperature range is '105 C. The pH is monitored and maintained in the alkaline range by the addition of alkalfmetal hydroxide and preferably the reaction takes place pI-Ifbetween 9.5 and 10.5.

HYDROLYSIS OF NITRILES It is of commercial note in assessing the present invention that the reduced copper oxide product in slurry form directly from the reduction process may be utilized together with an added nitrile such as acrylonitrile as input to the commercial hydrolysis of such nitrile to give yields of amide ranging from 75-94%.

EXAMPLE 1 1000 g. of cupric carbonate was charged into a stainless steel container and placed in a muflle furnace for 24 hours and 712 g. of cupric oxide were recovered.

A slurry was formed of 880 ml. of DI water and 53 g.

of cupric oxide produced above. The pH was regulated with sodium hydroxide to 10.85 and 0.5 g. of 50% nickel on kieselguhr clay carrier was utilized as a catalyst. The cupric slurry was placed under pressure of 203 p.s.i. with input hydrogen and temperature was maintained at 100- 103 C. for 3 hrs. 45 min.

At the end of the reaction time period, the pressure was returned to atmospheric and 420 g. of acrylonitrile were added directly into the now-reduced copper oxide slurry. Temperature was raised to about 108 C. and the pH was regulated in the acid range between 7.2 and 7.5 for 6.5 hours.

Analysis for amide showed 96.05% 96.33% (run 2) conversion.

EXAMPLE 2 880 ml. DI water, 53 g. copper II hydroxide from Rocky Mountain Research Corporation and 0.5 g. 50%

(run 1) and i nickel on kieselguhr clay were placed in a 2-liter autoclave and the pH adjusted to 9.88. Pressure of 202 p.s.i. was utilized with input hydrogen at a temperature of 100103 C. for 4 hours.

At the end of this time, the pressure was removed and directly into the autoclave was added 420 g. of acrylonitrile. The pH was lowered to 8.84 and a reaction temperature of 107 C. was maintained for about 7.5 hours.

Analysis of conversion to amide was 83.1%.

EXAMPLE 3 To a 5-liter, 3-necked flask was charged the following: 500 g. CuSO -5H O, 7.5 g. FeSO -7H O, 1500 m1. DI water, and 50 ml. 28% NH OH. Then was added 170 g. NaOH pellets dissolved in 1500 ml. DI water. The mixture -was heated to 70 C. and held for one hour and then oven dried at 110 C.

53 g. of the product from the above (cupric oxide) was mixed and slurried with 880 ml. DI water (boiled) and 0.5 g. of 53% nickel on a silica carrier. The pH was adjusted to 10.3 with a dilute sodium hydroxide solution. The reduction of the cupric ion was elfected by utilizing pressure of 230 p.s.i. with hydrogen at a temperature of 102-103 C. for 3 hours.

At the end of 3 hours pressure was reduced toatrnospheric and 420 g. of acrylonitrile was added to the product. The new reaction mixture was heated for 4 hours at 108109 C.

The amide conversion was 94.4%

EXAMPLE 4 In a manner similar to the experimental procedure'of Example 3 with the exception that 0.5 g. of a 60% nickel on a silica-alumina carrier (90:10), a 92.1% conversion was obtained.

EXAMPLE 5 In a manner similar to the experimental procedures of Example 1, the following additional runs were made and the results are summarized herein.

Amide Pressure conver- Temp. w/H: sion, range, Tlme, Input (grams) (p.s.i.) pH Range percent 0. hrs.

1,000 CuCOatCuO) 202 10-85-10. 20 94. 20 102-110 ca, 4. 5 53 Cl1(OH)z 225 9. 76. 00 100-105 ca 5 811(Sl96 fi 6 230 10. 15-9. 60 73. 05 100-102 ea 5. 5

11 a 2' z go gfi g 230 10. 50-10. 00 68. 00 101-103 ea 4 11 4- 2 go g g s g g 6 230 9. -9. 20 83. 20 98-101 ca 3 l1 4-5 2 l go g g g 3 512 6 230 9. ss-s. 65 76.80 99-100 ca 3 u 4- z 8 FGSOHHZO 230 9. -1130 89.73 100403 ca 3 230 l 9. 80-10. 02 82. 63 103 ea 5. 5

1,500 CuSO4'5HzO 25 FeSQWHZ O 230 10. 70-10. 48 86. 20 100-105 ca 2. 5

The embodiments of this invention in which an exclusive property or privilege is claimed are defined asfollows:

1. A method of producing a reduced copper oxide catalytically active slurry which comprises reacting an aqueous slurry of cupric oxide or cupric hydroxide or mixtures of cupric oxide and cupric hydroxide in the presence of a nickel catalyst under a hydrogen atmosphere for about 1-6 hours at from 100-105 C. whereby a catalytically active reduced copper oxide slurry is produced.

2. A method according to claim 1 wherein the catalyst is nickel coated on a carrier.

3. The method according to claim 2 wherein the catalyst is nickel coated on a kieselguhr clay carrier.

4. The method according to claim 2 wherein the catalyst is nickel coated on a silica carrier.

5. The :method according to claim 2 wherein the catalyst is nickel coated on an alumina carrier.

6. The method according to claim 2 wherein the catalyst is nickel coated on a silica-alumina carrier.

7. The method according to claim 2 wherein the carrier surface is coated with about 570% by weight of nickel.

8. The method according to claim 1 wherein the ratio of cupric oxide or cupric hydroxide or mixtures of cupric oxide and cupric to water in the aqueous slurry is about 1: 10 to 1:20.

9. The method according to claim 1 wherein the nickel catalyst is about 0.01 to 0.1% by weight of the slurry.

References Cited UNITED STATES PATENTS 3,597,481 8/1971 Te-fertiller et al. 260-561 R 3,631,104 12/1971 Habermann et al. 260--561 N 3,642,894 2/1972 Habermann et a1. 260-561 N PATRICK P. GARVIN, Primary Examiner A. P. DEMERS, Assistant Examiner U.S. Cl. X.R.

252-459, 466 I, 474, 476; 260--561 N, 561 R 

